The Spool Hub Eight-blade Windmill

Windmills and whirligigs are fascinating and inspiring. I enjoy researching and tinkering with whirligig designs and materials. My researching efforts led me to discover A. Neely Hall, the craftsman who authored the projects which my 2016 Newark Maker Faire exhibit is based on. His Eight-blade Windmill, utilizing a thread spool as a hub, is one of the projects I’ve been excited to try.

The illustration above, drafted excellently by Tom P. Hall, clearly describes the construction of the windmill. This windmill design is perfect for a beginner with limited tools because it eliminates sawing a precisely angled slot to hold the propeller in the hub. Here the hub is a wooden spool with holes drilled in even intervals around the circumference. Each propeller is attached to a spoke via clinched nails. A wood carving knife is used to whittle a point at one end of the spoke to fit into the hub.

Because I am building this project as part of my Maker Faire exhibit I am observing the original instructions as literally as possible. I whittled twenty four spokes to be used on the three windmills I am constructing. Poplar wood was used for the spokes. Most of the spokes had intentionally straight wood grain which aids in easy whittling. The propellers are 3/16″ plywood I had stored in the workshop. Generally I avoid using plywood because I find it doesn’t hold up to the elements, but it was on hand. Each propeller is clinched to the spokes by first driving the nail straight through the work, bending the shank with needle-nose pliers then flattening with a hammer.

Unfortunately a few spokes with less than ideal grain made their way into the project. I should have discarded the poorly grained spokes immediately, but I proceeded. While tapping the imperfect spokes into the hub a telltale cracking sound verified the mistake. The pointed ends snapped off before the spoke was completely seated. To repair the broken spoke I drilled the broken spoke wood from the spool, starting with a narrow drill bit and increasing width until the desired size hole returned. Then I drilled a one inch deep hole in the spoke where the whittled points broke off. I glued a hardwood dowel into the spoke to serve as a prosthesis which worked nicely.

I re-purposed the Unknot Shelf prototype (from a few weeks ago) into a stand to hold the assembled windmill propellers for brushing on paint. Each propeller will receive two coats of white paint followed by a coat or two of colorful details. These propellers will be used in a larger project in my Maker Faire exhibit, so you’ll be seeing more on these soon.